As many of you have probably found out, a small "blind spot mirror" does not work very well when mounted on the inboard part of the mirror (both on a car or a motorcycle). However, I found these small, adjustable, blind spot mirrors to work relatively well in that position. And as Jamie mentioned, they don't block any useful part of the bike mirror in that area.
The reason they work better than other spot mirrors is that the spot mirror base mounts on the bike mirror with the standard two sided tape, however, the spot mirror itself can be tilted out to give you a fairly good view of what would normally be your blind spot just behind and off to your side. No it doesn't eliminate the need to look over our shoulder before changing lanes, but I have found these small mirrors to be very beneficial in helping to see what is in that area.
They are less than $5 a pair but I have only been able to find them at Pep Boys Auto Parts stores (I assume they are a nationwide chain).
Here is another way to add spot mirrors to a GT model.
This allows you to add a 3" spot mirror (instead of the smaller ones), and places them further out, which gives you much larger field of view. I rode the bike with both and the smaller spot mirrors and the larger mirrors, and the 3" mirrors are much nicer.
Any metal fabricator could easily duplicate these in less than 1/2 hr but it is always easier when you already have an idea what somebody else did.
(Note: I plan to paint the mounting plates black so they will blend in with the plastic mirror pedestals and give it a stock appearance, but I left them natural aluminum for the picture)
I used:
Metal: 1/16" thick aluminum (6061 alloy) for the mounts (the two mounting holes are drilled 11/64").
Mounting Screws: # 8 X 9/16", Low Profile Phillips Drive.
I carefully drilled two small pilot holes (7/64"), into the BMW plastic mirror stems, for the screws to secure the mounting plates. Even though the plastic is fairly thick in that area drill slowly and do not let the drill go very far in.
(Note: After I paint the spot mirror mounting plates I also plan to glue them to the GT's plastic mirror stems, but for now the two small screws are holding them quite securely)
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The aluminum mounting plates are about 5-1/4" long (35mm), and 3-1/4" wide (82mm).
As you can see, they are very simple to make and it gives you a much larger, and safer, rear field of view. Moreover, once the mounts are painted black they should blend in with the stock mirrors and may even look like they came that way from BMW.
